Đáp án:`(sqrt6+sqrt{10})sqrt{4-sqrt{15}}=2`
Giải thích các bước giải:
`(sqrt6+sqrt{10})sqrt{4-sqrt{15}}`
`=sqrt2(sqrt3+sqrt5)sqrt{4-sqrt{15}}`
`=(sqrt3+sqrt5)sqrt{8-2sqrt{15}}`
`=(sqrt3+sqrt5)sqrt{5-2sqrt{5.3}+3}`
`=(sqrt3+sqrt5)sqrt{(sqrt5-sqrt3)^2}`
`=(sqrt3+sqrt5)|sqrt5-sqrt3|`
`=(sqrt5+sqrt3)(sqrt5-sqrt3)`
`=5-3`
`=2`.
Vậy `(sqrt6+sqrt{10})sqrt{4-sqrt{15}}=2`